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Background Immunosuppressive and biological medications are a mainstay in the treatment of immune-mediated diseases, such as inflammatory bowel diseases (IBD), rheumatic diseases, and psoriasis. However, the COVID-19 pandemic caused concerns over the safety of these drugs pertaining to risk and severity of infection with SARS-CoV2. Moreover, pandemic mitigation strategies may negatively impacted treatment start with immunosuppressive and biological treatment fostering worse long-term disease outcomes. The aim of this study was to examine the impact of the COVID-19 pandemic on new starts of immunosuppressive and biological treatment in Austria. Methods We conducted a retrospective analysis with a 4-year observation period from 2017 to 2020 on real-world data on prescriptions for immune-mediated diseases of the Austrian health insurance funds covering 98% of the Austrian population. Data from all patients with incident biologic or conventional immunosuppressive treatment (Table 1) were included. Incidence of biologic (including small molecules) and immunosuppressive therapy was defined as all first prescriptions of one of the listed substances from 2017. The incidence rate for biologic and immunosuppressive treatments was recorded monthly in 2020 and compared with the three previous years (2017 – 2019). Results During the first lockdown in Austria in spring 2020 (week 12 – week 20), there was a significant decrease in the overall starts of biologic (including small molecules) and immunosuppressive treatments (both p Conclusion In patients with immune-mediated diseases in Austria the COVID-19 pandemic led to a significant decrease of newly started immunosuppressive and biological treatments only during the first lock-down. Over the last four years, we can observe a continuous increase of small molecules and biological medication as well as a continuous decrease of conventional immunosuppressive medication.

BackgroundKnowledge about humoral and cellular immunogenicity and their kinetics following SARS-CoV-2 mRNA vaccinations in immunosuppressed patients is limited.MethodsAntibody and cytokine responses were assessed in 263 patients with either solid tumors (SOT, n=63), multiple myeloma (MM, n=70) or inflammatory bowel diseases (IBD, n=130) undergoing various immunosuppressive regimens and from 66 healthy controls before the first and the second, as well as four weeks and 5-6 months after the second mRNA vaccine dose with either BNT162b2 or mRNA-1273.FindingsFour weeks after the second dose, seroconversion was lower in cancer than in IBD patients and controls, with the highest non-responder rate in MM patients (17.1%). S1-specific IgG levels correlated with neutralizing antibody titers. While antibody responses correlated with cellular responses in controls and IBD patients, IFN-γ and antibody responses did not in SOT and MM patients. At six months, 19.6% of patients with MM and 7.3% with SOT had become seronegative, while IBD patients and controls remained seropositive in 96.3% and 100%, respectively. Vaccinees receiving mRNA-1273 presented higher antibody levels than those vaccinated with BNT162b2.InterpretationCancer patients may launch an inadequate seroresponse in the immediate time range following vaccination and up to six months, correlating with vaccine-specific cellular responses. These findings propose antibody testing in immunosuppressed - along with cellular testing - provides guidance for administration of additional vaccine doses, or may indicate the necessity for antibody treatment. IBD patients respond well to the vaccine, but treatment such as with TNF-α inhibitors may reduce persistence of immune responses.FundingThe study was sponsored and financed by the Medical University of Vienna – third party funding by the Institute of Specific Prophylaxis and Tropical Medicine. AOR. and HS acknowledge funding by the Austrian Science Fund (FWF, P 34253-B).

Background Crohn’s disease (CD) is associated with a high risk of intestinal complications such as stricture, fistula and abscess formation, as well as perianal disease, frequently requiring surgical procedures and intestinal stoma formation. The aim of the present study was to evaluate the prevalence as well as predictors for surgical stoma formation in CD patients. Methods This is a retrospective single tertiary center cohort study of 1157 patients with CD with a median follow-up of 15 years whose characteristics (Table 1) are recorded via a validated data software (IBDIS, Inflammatory Bowel Disease Information System). The primary objective was the assessment of risk factors for intestinal stoma formation during follow-up. The probability of stoma-free survival was calculated for the entire patient population and for subgroups defined by their time of diagnosis (-1999, 2000–2009, 2010-), location and behavior of disease, presence of perianal disease (ever), gender, and smoking habits by means of Kaplan-Meier estimates. Results 135 (11.7%) patients with intestinal stomas [78 (57.8%) ileostomies and 57 (42.2%) colostomies] were registered. The probability of stoma-free survival after 5, 10, and 20 years was 95.9%, 91.8%, and 85.5%, respectively. Stoma formation surgery was elective in 51 (37.8%) cases, emergency in 49 (36.3%) and unknown in the others (25.9%). The most common indications were perianal disease [(n=34; 25.2%), internal fistula/abscess [n=25 (18.5%)], postoperative complications [n=21 (15.6%)], stricture [n=11 (8.1%)], and refractory to treatment [n=10 (7.4%)]. The probability of stoma-free survival was significantly lower in patients with perianal disease (p Conclusion We found a high prevalence of intestinal stoma formation in CD patients of a tertiary center. Patients with perianal disease, penetrating behavior and colonic location, have a lower probability of stoma-free survival.

Aims: To isolate and characterize bacteria from the human intestine that are involved in the conversion of catechins, a class of bioactive polyphenols abundant in the human diet. Methods and Results: Two bacterial strains, rK3 and aK2, were isolated from an epicatechin-converting human faecal suspension. The isolates catalysed individual steps in the degradation of (−)-epicatechin and (+)-catechin. Based on their phenotypic characteristics and 16S rRNA gene sequences, the isolates were identified as Eggerthella lenta and Flavonifractor plautii (formerly Clostridium orbiscindens). Eggerthella lenta rK3 reductively cleaved the heterocyclic C-ring of both (−)-epicatechin and (+)-catechin giving rise to 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol. The conversion of catechin proceeded five times faster than that of epicatechin. Higher (epi)catechin concentrations led to an accelerated formation of the ring fission product without affecting the growth of Eg. lenta rK3. Flavonifractor plautii aK2 further converted 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol to 5-(3,4-dihydroxyphenyl)-γ-valerolactone and 4-hydroxy-5-(3,4-dihydroxyphenyl)valeric acid. Flavonifractor plautii DSM 6740 catalysed the identical reaction indicating it is not strain specific. Conclusions: The conversion of dietary catechins by the isolated Eg. lenta and F. plautii strains in the human intestine may affect their bioavailability. Significance and Impact of the Study: The majority of catechin metabolites are generated by the intestinal microbiota. The identification of catechin-converting gut bacteria therefore contributes to the elucidation of the bioactivation and the health effects of catechins.

The scratch resistance of polymeric clearcoats intended for automobile exterior surfaces was tested with scanning 3D nanoindentation and laboratory car wash simulation (AMTEC). It could be shown by using “real world” samples with comparable scratch resistance that the applied methods were suitable for discriminating even small differences in scratch resistance with high accuracy. In the area of physical characterization of scratch resistance, the results of this investigation demonstrate the ability of microscopic, single-contact testing methods to reproduce the macroscopically experienced results. By using a combination of different scratch methods, insight into the fundamentals, e.g., chemistry, that are responsible for good or bad scratch resistance, is achieved. One key for this goal is the imaging and analytical evaluation of the damage pattern after the indent, which leads to additional results and models presented in this article. It was found that an essential key to obtaining scratch resistant surfaces is a strengthening of rubber-like elasticity as well as minimizing interactions between individual polymeric chains.

Structured dispersion particles suitable for pressure sensitive adhesives (PSA) were synthesized via swelling polymerization technique (EP 359562). Particles consisting of poly(n-butyl acrylate) copolymerized with different types of carboxylic acids were used as seeds. The final particles were synthesized by swelling polymerization process, using 6 wt % styrene or 6 wt % methyl methacylate. The resulting particle morphology was analyzed by atomic force microscopy (AFM) and transmission electron microscopy (TEM). From previous works (Coll Surf A 2001, 183–185, 725–737; J Appl Polym Sci 2004, 91, 2610–2623) where two-step emulsion polymerization was used on similar particles, it is expected that the particle morphology is affected by the polarity of the monomer used for swelling polymerization because of the phase compatibility (thermodynamic parameter). In this work, the seed particles used were always of a glass transition temperature (Tg) below polymerization temperature. The diffusion of the growing polymer chains from the swelling polymerization is therefore mainly affected by their own Tg and the influence of the carboxy groups on the chain length of the entering radicals (kinetic parameter). The different morphologies of the single particles are discussed qualitatively. The effects of reaction parameters are compared with the results given in the previous work. The structure of the corresponding dispersion films was characterized using AFM. Correlations to macroscopic properties such as the cohesive strength and peel adhesion to different substrates are discussed. The results are also compared with the application properties of the corresponding unmodified particles, statistical copolymers, and to blends with small sized PMMA or PS particles. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1444–1455, 2006

The electronic structure and electron dynamics at a Si(100) surface is studied by two-photon photoemission (2PPE). At 90 K the occupied Dup dangling-bond state is located 150±50 meV below the valence-band maximum (VBM) at the center of the surface Brillouin zone Γ and exhibits an effective hole mass of (0.5±0.15)me. The unoccupied Ddown band has a local minimum at Γ at 650±50 meV above the VBM and shows strong dispersion along the dimer rows of the c(4×2) reconstructed surface. At 300 K the Ddown position shifts comparable to the Si conduction-band minimum by 40 meV to lower energies but the dispersion of the dangling-bond states is independent of temperature. The surface band bending for p-doped silicon is less than 30 meV, while acceptor-type defects cause significant and preparation-dependent band bending on n-doped samples. 2PPE spectra of Si(100) are dominated by interband transitions between the occupied and unoccupied surface states and emission out of transiently and permanently charged surface defects. Including electron–hole interaction in many-body calculations of the quasi-particle band structure leads us to assign a dangling-bond split-off state to a quasi-one-dimensional surface exciton with a binding energy of 130 meV. Electrons resonantly excited to the unoccupied Ddown dangling-bond band with an excess energy of about 350 meV need 1.5±0.2 ps to scatter via phonon emission to the band bottom at Γ and relax within 5 ps with an excited hole in the occupied surface band to form an exciton living for nanoseconds.

The signal produced in neutrino observatories by the pair-annihilation neutrinos emitted from a 20 $M_{\odot}$ pre-supernova star at the silicon burning phase is estimated. The spectrum of the neutrinos with an average energy $\sim$2 MeV is calculated with the use of the Monte Carlo method. A few relevant reactions for neutrinos and anti-neutrinos in modern detectors are considered. The most promising results are from $\bar{\nu}_e + p \longrightarrow n + e^{+}$ reaction. During the Si-burning phase we expect 1.27 neutrons/day/kiloton of water to be produced by neutrinos from a star located at a distance of 1 kpc. Small admixture of effective neutron-absorbers as e.g. NaCl or GdCl$_{3}$ makes these neutrons easily visible because of Cherenkov light produced by electrons which were hit by $\sim$8 MeV photon cascade emitted by Cl or Gd nuclei. The estimated rate of neutron production for SNO and Super-Kamiokande is, respectively, 2.2 and 41 events per day for a star at 1 kpc. For future detectors UNO and Hyper-Kamiokande we expect 5.6 and 6.9 events per day even for a star 10 kpc away. This would make it possible to foresee a massive star death a few days before its core collapse. Importance of such a detection for theoretical astrophysics is discussed., Comment: 18 pages, 2 figures, 5 tables, Astoparticle Physics: accepted for publication

Growth, thermal reaction, and crystalline structure of ultrathin iron silicide films on Si(111) are studied by low-energy electron diffraction (LEED) and Auger electron spectroscopy (AES). The structural development of silicide layers is monitored in dependence on iron coverage and annealing temperature. Below approximately 10 monolayers (ML) of iron, two film structures appear, that are not stable in bulk material, while above that limit a switch to the bulk structures is observed. The morphology of the films is strongly dependent on the growth conditions. Their homogeneity can be considerably improved by simultaneous deposition (coevaporation) of Fe and Si in the desired stoichiometry compared to annealing predeposited Fe films. This improvement is accompanied by the suppression of pinholes in the film. The Fe:Si stoichiometry of the (1×1) and (2×2) phase can be assigned 1:1 and 1:2, respectively. The crystal structure of the former was previously determined to be CsCl, so called c-FeSi. For codepositio...

Photons which constitute a shower image are not emitted simultaneously, but come from a range of shower front positions along the shower path. A spatial distribution of points of origin of photons arriving simultaneously to the eye is determined in this paper. Using realistic distribution of particles in a shower, and taking atmospheric scattering of light into account, the distribution of light arriving simultaneously to a detector is obtained. This instantaneous image (“a snapshot”) of the shower is independent of the detector properties – this is “what the shower looks like” when recorded with an ideal detector.

The dynamics of electrons in image-potential states has been studied by means of time- and energy- resolved two-photon photoemission. The loss of coherence in quantum-beat spectroscopy shows directly the influence of pure dephasing which can be determined also from the difference between the results of linewidth and decay rate measurements. We present several examples for the cor- relation of decay and dephasing with surface defects and disorder.

The study of the dynamics of electrons at metal surfaces is important for the understanding of photon or electroninduced chemical reactions in adsorbate overlayers [1]. Recent progress has been advanced by the generation of ultrashort laser pulses [2]. Two-photon photoelectron spectroscopy of image-potential states [3] permits the detailed study of the electron dynamics in the energy as well as in the time domain [4]. The results show a complex behavior of the measured decay time as a function of the energy analyzer detuning from the main peak and of the linewidth as a function of time delay between the two photon pulses [5]. A consistent description can be reached by the use of the Liouville-von Neumann equations [6,7]. The main parameters entering this picture are the true lifetime t of the image-potential state as well as the pure dephasing times T of the initial and intermediate states. The lifetime describes the decay of the population by inelastic scattering events and is measured in time-resolved experiments. Additional pure dephasing can be attributed to quasielastic scattering processes which do not change the population of the image-potential state but destroy the coherence between the involved states. This increases the measured energy width G compared to the value expected from the lifetime hyt. These processes are indicated in Fig. 1 together with the excitation scheme of two-photon photoemission. The true lifetime is understood fairly well theoretically by the decay of the image-state electron [8,9]. The results are closely related to the properties of hot electrons, because the decay of the image-potential states occurs mainly into metal bulk states. Using temperature-dependent measurements the quasielastic scattering by phonons could be identified and the results indicate bulklike values weighted by the probability of finding the electron inside the metal [7]. In this Letter we address surface-specific scattering processes induced by defects on the surface. As a model system we chose the adsorption of CO on Cu(100). This system shows a cs2 3 2d phase at half a monolayer (ML) coverage and a cs7 p 2 3 p 2 dR45± compression phase at

Construction of the first stage of the Pierre Auger Observatory has begun. The aim of the Observatory is to collect unprecedented information about cosmic rays above 10^18 eV. The first phase of the project, the construction and operation of a prototype system, known as the engineering array, has now been completed. It has allowed all of the sub-systems that will be used in the full instrument to be tested under field conditions. In this paper, the properties and performance of these sub-systems are described and their success illustrated with descriptions of some of the events recorded thus far., La lista completa de autores puede verse en el archivo asociado., Facultad de Ciencias Exactas

The performance of the Auger Fluorescence telescope is discussed on the basis of a mass production chain. In order to get a realistic estimate of the detector resolution, a large number of fully simulated CORSIKA showers have been used for this study. The propagation through the atmosphere and the detector response are taken into account and simulated in detail. Results for the the case of monocular reconstruction are presented here. No quality cuts for the event reconstruction have been applied so far. Finally, a schematic overview of the expected event topologies is given together with the display of a real event recently collected.

The structural properties of the system FeSi(111) developing upon the deposition of (sub)monolayer quantities of iron by solid-phase epitaxy and the early stages of silicide formation were investigated with low-energy electron diffraction (LEED), Auger electron spectroscopy (AES) and scanning tunneling microscopy (STM). AES data indicate that the iron-silicon (silicide) reaction starts well below room temperature. Independent of the amount of iron deposited, i.e. up to 7 monolayers (ML), two distinct film structures, namely a (1 × 1) and a (2 × 2) phase form at different annealing temperatures. Substantial differences between the two phases in stoichiometry and structure are indicated by AES amplitudes as well as LEED intensities (IV spectra). Three types of islands or film patches are observed by STM for the (2 × 2) phase, exhibiting different growth modes. Nevertheless, we find the same adatom termination in (2 × 2) arrangement on all types of islands. Combination of the LEED, AES and STM results suggests that film growth is incomplete, with different amounts of clean surface areas exposed depending on the initial coverage (Θ). For Θ ≤ 5 ML the crystalline structures of the film patches are probably similar for each phase at different coverages, but different between the (1 × 1) and the (2 × 2) phases.

To isolate and characterize bacteria from the human intestine that are involved in the conversion of catechins, a class of bioactive polyphenols abundant in the human diet.Two bacterial strains, rK3 and aK2, were isolated from an epicatechin-converting human faecal suspension. The isolates catalysed individual steps in the degradation of ⁻-epicatechin and ⁺-catechin. Based on their phenotypic characteristics and 16S rRNA gene sequences, the isolates were identified as Eggerthella lenta and Flavonifractor plautii (formerly Clostridium orbiscindens). Eggerthella lenta rK3 reductively cleaved the heterocyclic C-ring of both ⁻-epicatechin and ⁺-catechin giving rise to 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol. The conversion of catechin proceeded five times faster than that of epicatechin. Higher (epi)catechin concentrations led to an accelerated formation of the ring fission product without affecting the growth of Eg. lenta rK3. Flavonifractor plautii aK2 further converted 1-(3,4-dihydroxyphenyl)-3-(2,4,6-trihydroxyphenyl)propan-2-ol to 5-(3,4-dihydroxyphenyl)-γ-valerolactone and 4-hydroxy-5-(3,4-dihydroxyphenyl)valeric acid. Flavonifractor plautii DSM 6740 catalysed the identical reaction indicating it is not strain specific.The conversion of dietary catechins by the isolated Eg. lenta and F. plautii strains in the human intestine may affect their bioavailability.The majority of catechin metabolites are generated by the intestinal microbiota. The identification of catechin-converting gut bacteria therefore contributes to the elucidation of the bioactivation and the health effects of catechins.

Nanostructured products or products which were developed by means of nanotechnology already exist in the field of construction chemistry or construction materials. Main driving force in the conservative construction industry to invent or adopt new technologies is to reduce energy (CO2-footprint) during the construction process as well as during the utilization of buildings. Additional targets are increased service lifetimes of the constructions or new functionalities. E.g. photocatalytically active surfaces to reduce staining and increase air quality.The performance advantages of materials in the field of thermal insulation foams (nanofoams), nanocomposite colloidal particles (polymeric binders) and nanotechnologically improved inorganic binder systems have been investigated and will be discussed.

We discuss important issues which are essential for understanding future capabilities of the large water Cherenkov detectors from astrophysical point of view. The paper is concentrated on the detection of the neutrinos, which are emitted before core‐collapse from massive stars.

Magnetic properties of the neutron star matter are determined by the behaviour of protons which form a dilute component of the neutron star core [1]. Protons are likely to localize at high densities [2, 3]. This is a result of nuclear interactions which at high densities favour a single-isospin system [4, 5]. Localized protons would form a crystal structure at low temperatures [6]. Such a proton crystal has a single proton localized inside every elementary cell. As we showed in Ref. [I], neutron star matter with localized protons is unstable with respect to spin fluctuations. It is easy to see that a single proton, which has a well-defined spin, will polarize surrounding neutron matter, as there exists direct proton-neutron spin interaction. This induced polarization of the neutron Fermi sea can in turn polarize neighbouring localized protons. This means that the RKKΥ (Ruderman—Kittel-KasuyaYoshida) [7] mechanism can operate and a long-range spin order can propagate in the proton crystal. Nuclear forces are strongly spin-dependent. For our purpose here it is useful to approximate the spin potential by a contact potential with a suitably chosen coupling constant [1]. For studying a system of protons localized in potential wells due to density variation of the neutron background the relevant spin potential is

Carrier recombination at the Si(100) $c(4\ifmmode\times\else\texttimes\fi{}2)$ surface and the underlying surface electronic structure is unraveled by a combination of two-photon photoemission and many-body perturbation theory: An electron excited to the silicon conduction band by a femtosecond infrared laser pulse scatters within 220 ps to the unoccupied surface band, needs 1.5 ps to jump to the band bottom via emission of optical phonons, and finally relaxes within 5 ps with an excited hole in the occupied surface band to form an exciton living for nanoseconds.

The cooling of neutron stars by URCA processes in the kaon-condensed neutron star matter for various forms of nuclear symmetry energy is investigated. The kaon-nucleon interactions are described by a chiral lagrangian. Nuclear matter energy is parametrized in terms of the isoscalar contribution and the nuclear symmetry energy in the isovector sector. High density behaviour of nuclear symmetry energy plays an essential role in determining the composition of the kaon-condensed neutron star matter which in turn affects the cooling properties. We find that the symmetry energy which decreases at higher densities makes the kaon-condensed neutron star matter fully protonized. This effect inhibits strongly direct URCA processes resulting in slower cooling of neutron stars as only kaon-induced URCA cycles are present. In contrast, for increasing symmetry energy direct URCA processes are allowed in the almost whole density range where the kaon condensation exists., Comment: 19 pages, 8 figures, elsart class

The influence of the nuclear symmetry energy on the formation of a mixed quark-nucleon phase in neutron star cores is studied. We use simple parametrizations of the nuclear matter equation of state, and the bag model for the quark phase. The behavior of nucleon matter isobars, which is responsible for the existence of the mixed phase, is investigated. The role of the nuclear symmetry energy changes with the value of the bag constant B. For lower values of B the properties of the mixed phase do not depend strongly on the symmetry energy. For larger B we find that a critical pressure for the first quark droplets to form is strongly dependent on the nuclear symmetry energy, but the pressure at which last nucleons disappear is independent of it., 12 pages, 16 figures, Phys. Rev. C in press

A model of the ferromagnetic origin of magnetic fields of neutron stars is considered. In this model, the magnetic phase transition occurs inside the core of neutron stars soon after formation. However, owing to the high electrical conductivity the core magnetic field is initially fully screened. We study how this magnetic field emerges for an outside observer. After some time, the induced field that screens the ferromagnetic field decays enough to uncover a detectable fraction of the ferromagnetic field. We conjecture that weak fields of millisecond pulsars of 10^8-10^9 G could be identified with ferromagnetic fields of unshielded fraction f=10^-4 resulting from the decay of screening fields by a factor 1-f in 10^8 yr since their birth., 5 pages, 2 figures, MNRAS in press

The relaxation dynamics of the image-potential states of Cu(100) under the influence of CO adsorption is investigated by time-resolved Two-Photon Photoemission Spectroscopy (2PPE). Pure dephasing due to elastic scattering leads to a fast decay of quantum-beat patterns of energetically close-lying image states at already very low CO coverages. For higher CO exposure an increase in structural order is correlated with a decrease in pure dephasing rates.

Relativistic mean field (RMF) theory of nuclear matter with the isovector scalar mean field corresponding to the delta-meson [a_0(980)] is studied. While the delta-meson mean field vanishes in symmetric nuclear matter, it can influence properties of asymmetric nuclear matter in neutron stars. The RMF contribution due to delta-field to the nuclear symmetry energy is negative. To fit the empirical value, E_s=30 MeV, a stronger rho-meson coupling is required than in the absence of the delta-field. The energy per particle of neutron matter is then larger at high densities than the one with no delta-field included. Also, the proton fraction of beta-stable matter increases. Splitting of proton and neutron effective masses due to the delta-field can affect transport properties of neutron star matter., 13 pages, plain TeX, 6 figures, Physics Letters B in press

The occupied and unoccupied electronic structure of thin epitaxial CoSi(2) films grown on Si(111) substrates was studied using time-resolved two-photon photoemission and valence-band photoemission spectroscopy. The work function of the sample surfaces and the Schottky barrier height at the metal-semiconductor interface were measured as a function of annealing temperature. The photoemission data reveal several occupied and unoccupied electronic states which exhibit a high sensitivity to the annealing temperature. Time-resolved measurements show a behavior typical for a short-lived hot-electron gas and indications for an image-potential resonance.

We study proton impurities in dense neutron matter and show that they behave as polarons which are localized at high densities. The phase with localized protons displays a ferromagnetic instability. Permanently magnetized matter inside a neutron star can produce the magnetic field of the star. The model explains the accretion-induced magnetic field decay observed for millisecond pulsars and binary pulsars.

The momentum distributions are calculated for the pions and protons which are produced in a proton-nucleus collision. We assume that in each nucleon-nucleon interaction a quark or a quark-antiquark pair is removed from the projectile. The final hadron distribution can then be expressed in terms of quark distribution functions and fragmentation functions which are both taken from lepton-nucleon collisions.

We estimate the properties of dense matter in a chiral bag model, using methods previously employed for skyrmions. The bag is stabilized by the Casimir energy, and the chiral field outside the bag is described by Skyrme's model. We find that the bag radius decreases with increasing density, but that the fraction of space filled by bags increases. We also investigate the transition to quark matter.

Inclusive cross sections for proton collisions on nuclei, pA→pX, are decomposed into a sum of contributions fx(x, p ⊥) for a proton collision with exactly n nucleons. We describe a method how to obtain the distributions fnx, p ⊥) from the data and apply it to pA experiments at 100 GeV/c. The function f1(x, p ⊥) drastically differs from those with n ⩾ 2.

Magnetoresistance of the CLTS temperature sensor was determined in dependence on field and temperature. Based on its significant negative magnetoresistance and due to its small dimensions this sensor can be used to measure magnetic field within superconducting magnet windings. This method has been applied in the 3 coil arrangement of our superconducting TESPE torus magnet system and good agreement has been found with calculated field data.

We calculate the inclusive momentum distribution of particles produced in a hadron-nucleus (hA) collision. The exchange of colour between the projectile and target nucleons leads to the formation of colour strings which are assumed to fragment like strings formed in deep inelastic lepton-nucleon scattering. Making a few basic hypotheses we consistently and parameterfree describe the projectile fragmentation region in collisions of the typehA→h′X withh=p, π+ andh′=p, π+, π− at 100 GeV incident energy.

Multiplicity distributions of charged particles produced in collisions of ultrarelativistic protons with nuclei are studied in a string model. Recently measured multiplicity distributions in proton-nucleus reactions display a negative binomial shape. The string model VENUS reproduces the data well. We trace back within the model the origin of the negative binomial form of the multiplicity distributions. We find that the final multiplicity distribution can be expressed as a continuous superposition of Poisson distributions with different mean multiplicities ∫dNW(N)P(N, n). The Poisson distribution represents the string fragmentation, whereas the weight factorW(N) reflects the string mass distribution. This quantity has contributions due to both the nuclear structure and the parton structure of nucleons. We show thatW(N) is very well approximated by a gamma-distribution . This leads to a negative binomial distribution\(\mathcal{N}(k,\bar N;n)\) with the same parameters as for . It is shown that the fluctuations in the multiplicity are dominated by the string fragmentation fluctuations for small rapidity intervals and by string mass and number fluctuations for large rapidity windows.

We explore some properties of dense matter in Skyrme's chiral soliton model and show that at high densities the energy density varies as ${n}^{\frac{4}{3}}$, where $n$ is the baryon density. This is quite different from the behavior of conventional nuclear models, but is very similar to that of quark matter. The maximum mass of neutron stars constructed of such matter is significantly lower than that for most other versions of dense matter and may account for the absence of neutron stars in many extended supernova remnants. The phase transition to quark matter is expected to be softened considerably by such a nuclear-matter model.

We investigate multiplicity distributions in ultrarelativistic proton-nucleus collisions in a string model approach. We try to disentangle the different sources of multiplicity fluctuations: nuclear structure, the parton structure of nucleons and the fragmentation of colour strings. We show that the multiplicity distribution can be written as a continuous superposition ∫ d N W (N) P (N;n) of poissonian distributions P with variable mean values N, the weight factor W (N) representing nuclear and nucleonic structure, whereas the poisson distribution P reflects fluctuations due to string fragmentation. By using the string model VENUS, we show that W (N) can be well approximated by a gamma distribution G (k, N ;N) , leading to a negative binomial distribution N (k, N ;n) for the multiplicity distribution, with the same parameters as for G ! This has interesting consequences: for small 〈n〈 (small rapidity window) the fragmentation fluctuations dominate; for large 〈n〉 they are negligible!

The recently proposed model of pion condensation consistent with the known properties of nuclear matter is extended to include the π-ϱ interactions. The relevant coupling constant is chosen so as to account for the symmetry energy. No pion condensation is found in nuclear matter.